Coca Cola Plans High Tech, Super Cool Sprite

Coca Cola’s new experimental Sprite Super Chilled deals a double blow to environmentalists: First, it comes in a specially engineered bottle, second, it needs a new kind of vending machine.

The premise is that we like our soft drinks over ice, but we don’t like the dilution. Coca Cola’s new machine keeps the Sprite very cold. After vending, you twist the bottle and some secret magic freezes part of the drink.

Sprite Super Chilled could go on sale next year. It seems like a gimmick, and so far there are no technical details, but we have some idea of how it might work. Here’s the science bit:

Water can cool to below 0ºC (32ºF) and remain liquid. This is called supercooling. In order to change state from liquid to solid, there need to be “nucleation sites” present in the water. These can be bubbles or impurities, and if introduced to supercooled water, it freezes instantly. It’s similar to how a pan of boiling water goes crazy when you throw in salt: The salt doesn’t lower the boiling point (or not enough to matter) – it creates nucleation sites so the water turns to steam more easily.

This can be seen in a bottle of sparkling water. Restaurant fridges are often very cold. Take a bottle out and crack the lid. As the CO2 comes out of solution, the bubbles form nucleation sites and the ice suddenly crystallizes. It’s pretty spectacular, and rare. My guess is that the new vending machine keeps the Sprite below zero, and the twist causes this instant freezing.